Overrunning clutch for use in an automotive power transmission

ABSTRACT

An overrunning clutch adapted to permit free rotation of the inner and outer wheels with respect to each other when one of the inner and outer wheels rotates in one direction. Either one of the inner and outer wheels is formed with at least three radially extending projecting portions at circumferentially equally spaced positions, which projecting portions engage with the opposing peripheral wall of another one of the inner and outer wheels to prevent deflection of the inner and outer wheels with respect to each other, and at least two cam surfaces at circumferentially equally divided positions between the adjacent projecting portions. At least two rollers are disposed about the cam surfaces between the inner and outer wheels so that the smooth operation is obtained.

United States Patent [1 1 Ohtsuka et al.

[ 1 OVERRUNNING CLUTCH FOR USE IN AN AUTOMOTIVE POWER TRANSMISSION [211pp No.: 243,

[30] Foreign Application Priority Data Aug. 20, 1971 Japan 46/74290 Aug.23, 1971 Japan 46/74892 [52] US. Cl .192/45, 192/48.92, 192/85 AA,192/109 R, 188/71.5, 188/8284 [51] Int. Cl. Flfid 41/06 [58] Field ofSearch 192/45, 48.3, 48.92, 192/85 AA, 109 R; 188/8284, 71.5

[56] References Cited UNITED STATES PATENTS 9/1962 Fahlberg 192/458/1895 Hargraves.... 192/45 X 3/1907 King 192/45 X [11 3,750,783 [4 1Aug.7, 1973 Primary Examiner-Allan D. Hermann Attorney-John Lezdey [57]ABSTRACT An overrunning clutch adapted to permit free rotation of theinner and outer wheels with respect to each other when one of the innerand outer wheels rotates in one direction. Either one of the inner andouter wheels is formed with at least three radially extending projectingportions at circumferentially equally spaced positions, which projectingportions engage with the opposing peripheral wall of another one of theinner and outer wheels to prevent deflection of the inner and outerwheels with respect to each other, and at least two cam surfaces atcircumferentially equally divided positions between the adjacentprojecting portions. At least two rollers are disposed about the camsurfaces between the inner and outer wheels so that the'smooth operationis obtained.

5 Claims, 4 Drawing Figures PAIENIEU M18 3.750.783

sum 1 or 2 OVERRUNNING CLUTCH FOR USE IN AN AUTOMOTIVE POWERTRANSMISSION This invention relates in general to overrunning clutchesand, more particularly, to an overrunning clutch for use in anautomotive automatic power transmission including a hydrodynamic torqueconverter and-a planetary gear set.

An overrunning clutch employed in an automotive automatic powertransmission commonly includes a cylindrical inner wheel and acylindrical outer wheel which is formed at its inner wall a plurality ofcam surfaces. A plurality of rollers are disposed about these camsurfaces between the inner wall of the outer wheel and an outer surfaceof the inner wheel. With this construction, the overrunning clutchfunctions to permit free rotation of the inner and outer wheels withrespect to each other when one of the inner and outer wheels rotate inone direction. When, however, the one of the inner and outer wheelsrotate in another or reverse direction, the rollers functions to wedgebetween the outer surface of the inner wheel and the cam surfaces on theouter wheel thereby to inhibit free rotation of the inner and outerwheels with respect to each other. A difficulty is encountered in thisprior overrunning clutch in that the center of the inner wheel isdeviated from that of the outer wheel during rotation. To eliminate thisdifficulty, it has heretofore been proposed to provide a plurality ofprojection portions on the inner wall of the outer wheel whichprojecting portions extend radially inwardly from the inner wall of theouter wheel and which engage the outer surface-of the inner wheel. Theprovision of these projecting portions is, however,.refelcted bydecrease in the number of rollers so that it is quite difficult toobtain smooth rotation of the movable members.

In the automotive automatic power transmission, the overrunning clutchis sized to be mounted in a limited space to reduce the size of theautomaitc power transmission. This overrunning clutch is mounted in theautomatic power transmission in such a manner that the cylindrical outerwheel is press fitted into a bore formed in a casing body of the powertransmission whereas the cylindrical inner wheel is. rotatably connectedto a rotatable member such as driving shaft. With this construction,when thrust is exerted on the driving shaft, the inner wheel connectedtherewith tends to move in axial direction thereby causing the rollerstomove in the same direction. At the same time, the outer wheel is causedto axially move out of the associated bore in the casing body of thepower transmision due to the thrust applied to the driving shaft. Toeliminate this drawback, it is requisite that the overrunning clutch beprovided with additional component parts which leads to increase in itsmounting space.

It is, therefore, an object of the present invention to provide animproved overrunning clutch which is adapted not only to smoothlyoperate but to prevent deflection of the movable part relative to thestationary part.

It is another object of the present invention to provide an improvedoverrunning clutch which is specifically suited for use in an automotiveautomatic power transmission.

It is a further object of the present invention to provide an improvedoverrunning clutch for use in an automotive automatic powertransmission, which clutch is adapted to prevent axial movement ordeflection of the rollers and movable part with respect to thestationary part of the automotive automatic: power transmission. Ingeneral, these objects of the: present invention is achieved by anoverrunning clutch which includes a cylindrical inner wheel and acylindrical outer wheel. In one preferred embodiment, cylindrical outerwheel has a cylindrical inner wall on which at least three projectingportions are formed at circumferentially equally spaced positions. Theprojecting portions extend axially inwardly from the cylindrical innerwall of the outer wheel and engage the cylindrical outer wall of theinner wheel. The cylindrical inner wall of ,the outer wheel is furtherformed with at least two cam surfaces at circumferentially equallydivided positions between the adjacent projecting portions extendinginwardly from the cylindrical inner wall of the outer wall. Rollers aredisposed between the cylindrical outer wall of the inner wheel and thecam surfaces on the outer wheel. The overruning clutch also includes aflange portion which extends radially outwardly from the outer wall ofthe outer wheel and which abuts against a side. wall of a casing body ofan automotive automatic power transmission. The outer wheel has anannular shoulder portion formed in the cylindrical inner; wall thereofinto which an annular thrust plate is fixedly disposed which preventsaxial movement of the rollers with respect to the outer wheel. Aplurality of thrust bearing rollers are member fixed to the inner wheelso that the thrust exerted on the drum member and the inner wheel istransmitted through the thrust bearing rollers to the anular plate fromwhich the thrust is delivered through the flange portion formed on theouter wheel to the casing body of the automatic power transmission.

These and other objects and advantages of the present invention willbecome more apparent vfrom the following description when taken inconjunction with. the accompanying drawings in which same referencenumeral are used to designate like or corresponding component parts andin which:

FIG. I is a side view of a preferred embodiment of an overrunning clutchaccording to the present invention;

FIG. 2 is a sectional view of the overrunning clutch taken on line II-IIof FIG. 1; V 3

FIG. 3 is a side view of a modified form of the oven running clutchaccording to the present inventiomand FIG. 4 is a sectional viewv ofanother preferred embodiment of the overrunning clutch according to thepresentinvention, the overrunning clutch being shown as incorporated inan automotive automatic power transmission. V i Q j Referring now to thedrawings and more particularly to FIGS. 1 and 2, there is shown apreferred embodiment of the overrunning clutch implementing the presentinvention. The overrunning clutch proposed by the present invention isspecifically suited for use in an automotive automatic powertransmission as will be described hereinafter in detail. The:overrunning clutch, which is generally designated by reference numeral10, includes a cylindrical outer wheel 12 which has a knurled surface124 formed at its outer peripheral wall. This outer wheel 12 may befixedly mounted within a casing body (not shown) of an automotiveautomatic power transmission as will be discussed hereinafter.

According to an important feature of the present invention, thecylindrical outer wheel 12 is formed at its cylindrical inner wall (notidentified) at circumferentially equally spaced poistions with at leastthree projecting portions 14 which extend radially inwardly from thecylindrical inner wall of the outer wheel 12. Each of these projectingportions 14 has an inner peripheral wall 140 which engages an outerperiphral wall 16a of a cylindrical inner wheel 16, which is drivablyconnected to and rotatable with a driving shaft 18 of the automotiveautomatic power transmission (not shown). As seen in FIG. 1, the outerwheel 12 is further formed at its cylindrical inner peripheral wall withcam surfaces or inclined surfaces 20 each inclined at the same anglewith respect to the center of the overrunning clutch 10. These camsurfaces 20 are formed at circumferentially equally divided positions.Similar rollers 22 corresponding in number to the cam surfaces 20 aredisposed between the cam surfaces 20 on the outer wheel 12 and thecylindrical outer peripheral wall 16a of the inner wheel 16. g

It should be noted that although the projecting portions 14 and the camsurfaces 20 are shown as formed on the inner peripheral wall of theouter wheel 12 in FIG. 1, these may be formed on the outer periphralwall of the inner wheel in a manner as will be described in detail.

When, in operation, the driving shaft 18 rotates counterclockwise asviewed in FIG. 1, the rollers 22 are moved in the same direction due tothe frictional force.

Consequently, the rollers 22 are released from wedged.

condition between the outer peripheral wall 16a of the inner wheel 16and the cam surfaces 20 formed on the outer wheel so that the innerwheel 16 and accordingly the driving shaft 18 are freely rotatable withrespect to the outer wheel 12. Since, in this condition, the projectingportions 14 on the outer wheel 12 engage at its peripheral wall 14a theouter peripheral wall 16a of the inner wheel 16, the inner wheel 16 isprevented from being deflected from the center of the outer wheel 12.

When, in contrast, the driving shaft 18 tends to rotate in clockwisedirection as viewed in FIG. 1, the rollers 22 are caused to wedgebetween the outer peripheral wall 16a of the inner wheel 16 and the camsurfaces 20 formed in the inner peripheral wall of the outer wheel 12.Accordingly, the driving shaft 18 and accordingly the inner wheel 16 areprevented from being rotated in the clockwise direction because theouter wheel 12 is fixed to the stationary part or casing body of theautomaitc power transmission or previously described.

It should be born in mind that, in the illustrated embodiment, theoverrunning clutch of the present invention is shown and described ashaving the inner wheel being rotatable in one direction with respect tothe outer wheel but the inner wheel may be held stationary while theouter wheel is made rotatable in one direction.

FIG. 3 illustrates a modified form of the overrunning clutch accordingto the present invention. In this modification, the projecting portionindicated at 14' are formed on the inner wheel 16 at circumferentiallyequally spaced positions and engage the inner peripheral wall l2b of theouter wheel 12. Moreover, the cam surfaces 20' are formed on the innerwheel at circumferentially equally divided positions between theadjacent projection portions 14 and the rollers 22 are disposed betweenthese cam surfaces 20' and the inner peripheral wall l2b of the outerwheel. The operation of the overrunning clutch is similar to that of theoverrunning clutch shown in FIGS. 1 and 2, and, therefore, the detaildiscussion of the same is herein omitted for the sake of simplicity ofillustration.

Another preferred embodiment of the overrunning clutch according to thepresnet invention is illustrated in FIG. 4, wherein like component partsare designated by the same reference numerals as those used in FIGS. 1and 2 with the exception that a double prime has been added to those. Inthis illustrated embodiment, the overrunning clutch 10" is shown asincorporated in a usual automotive automatic power transmission, a partof which is shown in FIG. 4. In FIG. 4, the automatic power transmissionindicated at 30 is shown to have a drum member 32 which is fixedlyconnected to the inner wheel 16" of the overrunning clutch l0" and whichis connected to a part 34. As shown, the overrun ning clutch 10" isfixedly mounted within a bore 36a formed in a casing body 36. The casingbody 36 is formed with a spline 38 to which a retainer plate 40 issecured. A plurality of driving disc plates 42 are splined to the spline38 on the casing body 36 and are axially slidable. A plurality of drivendisc plates 44 are interleaved between the plurality of driving discplates 42 and splined to a spline (not identified) formed on the drummember 32 to be axially movable. To actuate these disc plates. 42 and44, a fluid pressure operated servo piston 46 is provided which areaxially slidable disposed in a fluid chamber 48 formed in the casingbody 36 and which is movable in a position to cause the disc plates 42and 44 to engage with each other when the" fluid pressure is supplied tothe fluid chamber 48. A return spring 50 which is in the form of anannular Belleville washer is associated with the fluid pressure operatedservo piston 46 to bias the same in the disengagement position.

According to another important feature of the present invention, theoverrunning clutch 10" also includes a flange portion 52 which extendsradially outwardly of the peripheral wall of the outer wheel 12" andwhich abuts against the side wall (not identified) of the casing body36. The outer wheel 12" has an annular shoulder portion 54 into which anannular thrust plate 55 is fixedly disposed which prevents axialdisplacement of the rollers 22" in association with a snap ring 56 whichis fixed to the outer wheel 12". A plurality of thrust beariing rollers58 are disposed between the annular thrust plate 55 andthe drum member32 so that the force F applied to the part 34 is transmitted to thethrust plate 55. When assembling, the outer wheel 12" is press fittedinto the bore 360 of the casing body 36 until the flange portion 52 onthe outer wheel 12" abuts against the side wall of the casing body 36.

When, in operation, the fluid pressure is not supplied to the fluidchamber 48, the fluid pressure operated servo piston 46 is movedrightwardly of the drawing by the action of the return spring 50.Consequently, the disc plates 42 and 44 are maintained in theirdisengagement position and, thus, the drum member 32 and the inner wheel16" are rotatable in a direction as permitted by the overrunning clutch10''.

When, however, the fluid pressure is supplied to th fluid chamber 48,the fluid pressure operated servo piston 46 is moved leftwardy of thedrawing against the force of the return spring 50. In this instance, thedisc plates 42 and 44 are pressed against the retainer plate 40 andengage with each other so that the drum member 32 and the inner wheel16'' are held stationary with respect to the casing body 36. When thistakes place, the inner wheel 16" is prevented from being rotatated ineither direction.

It will be appreciated that, during these operations, if the force F isapplied to the drum member 32 this force F is transmitted to the casingbody 36 through the thrust bearing rollers 58 and the annular thrustplate 55 thereby to prevent transmission of the thrust to the innerwheel 16" for inhibitting axial displacement of the inner wheel 16" withrespect to the casing body 36. Since, in this condition, the rollers 22"are disposed between the thrust plate 55 and the snap ring 56 with acertain clearance so that no thrust is exerted on the rollers 22''.

It will now be understood that the overrunning clutch embodying thepresent invention smoothly operates without causing deflection of themovable part with respect to the stationary part.

It will also be noted that the overrunning clutch according to thepresent invention effectively prevents axial deflection of the rollersand movable part with respect to the stationary parts even when thethrust is exerted thereon.

What is claimed is:

1. An overrunning clutch comprising an inner wheel having an outerperiphral wall, an outer wheel facing said outer peripheral wall of saidinner wheel having an inner peripheral wall, at least three radiallyextending projecting portions provided on either one of said outerperipheral wall of said inner wheel and said inner peripheral wall ofsaid outer wheel at circumferentially equally spaced positions, saidprojecting portions engaging another one of said outer peripheral wallof said inner wheel and said inner peripheral wall of said outer wheel,a plurality of cam surfaces provided on said either one of said outerperipheral wall of said inner wheel and said inner peripheral wall ofsaid outer wheel at circumferentiallyequally divided positions betweenadjacent said projecting portions, each of said cam surfaces beinginclined at the same angle with respect to the center of saidoverrunning clutch, and a plurality of rollers disposed between said camsurfaces and said another one of said outer peripheral wall of saidinner wheel and said inner peripheral wall of said outer wheel.

2. An overrunning clutch comprising an inner wheel having an outerperipheral wall, an outer wheel having an inner peripheral wall facingsaid outer peripheral wall of said inner wheel, at least threeprojection portions radially inwardly extending from said innerperipheral wall of said outer wheel at circumferentially equally spacedpositions, said projecting portions each having a peripheral wallengaging said outer peripheral wall of said inner wheel to preventeccentricity of said inner wheel with respect to said outer wheel, aplurality of cam surfaces formed on said inner peripheral wall of saidouter wheel at circumferentially equally divided positions betweenadjacent said projecting portions, each of said cam surfaces beinginclined at the same angle with respect to the center of saidoverrunning clutch, and a plurality of rollers disposed in between saidouter peripheral wall of said inner wheel and said cam surfaces formedon said inner peripheral wall of said outer wheel, said rollers beingcapable of contacting said outer peripheral wall of said inner wheel andsaid cam surfaces on said outer wheel, whereby said inner wheel isprevented from rotation in one direction with respect to said outerwheel.

3. An overrunning clutch comprising an inner wheel having an outerperipheral wall, an outer wheel having an inner peripheral wall facingsaid outer peripheral wall of said inner wheel, at least threeprojecting portions radially outwardly extending from said outerperiphral wall of said inner wheel at circumferentially equally spacedpositions, said projecting portions each having a peripheral wallengaging said inner peripheral wall of said outer wheel to preventeccentricity of said outer wheelwith respect to said inner wheel, aplurality of cam surfaces formed on said outer peripheral wall of saidinner wheel at circumferentiallyequally divided positions between saidadjacent projecting portions, each of said cam surfaces being inclinedat the same angle with respect to the center of said overrunning clutch,and a plurality of rollers disposed in between said cam surfaces on saidinner wheel and said inner peripheral wall of said outer wheel, saidrollers being capable of contacting said inner peripheral wall of saidouter wheel and said cam surfaces on said inner wheel, whereby saidouter wheel is prevented from rotation in one direction with respect tosaid. inner wheel.

4. An overrunning clutch for an automotive automatic power transmissionhaving a casing body and a drum member, said overrunning clutchcomprising an inner wheel connected to said drum member and having anouter peripheral wall, an outer wheel press fitted into a bore of saidcasing body a flange portion extending radially outwardly from the outerperipheral wall of said outer wheel and abutting against said casingbody, an annular shoulder portion formed in said peripheral wall of saidouter wheel, an annular thrust plate fixedly disposed in said annularshoulder portion on said outer wheel, and a plurality of thrust bearingrollers disposed between said drum member and said thrust platetotransmit the thrust exerted on said drum member to said casing bodythrough said thrust plate on said annular shoulder portion of said outerwheel.

5. An overrunning clutch for an automotive automatic power transmissionhaving a casing body and a drum member, said overrunning clutchcomprising an inner wheel connected to said drum member and having'anouter peripheral wall, an outer wheel press fitted to a bore of saidcasing body and. having an inner pe ripheral wall, at least threeradially extending projecting portions provided on either one of saidouter peripheral wall of said inner wheel and said inner peripheral wallof said outer wheel at circumferentially equally spaced positions, saidprojecting portions engaging another one of said outer peripheral wallof said inner wheel and said inner peripheral wall of said outer wheel,at least two cam surfaces provided on said either one of said outerperipheral wall of said inner wheel and said inner periphral wall ofsaid outer wheel at circumferentially equally divided positions betweenadjacent said projecting portions, at least two rollers disposed aboutsaid cam surfaces between said outer peripheral wall of said inner wheeland said inner periphral wall of said outer wheel, a flange portionextending radially outwardly from the outer peripheral wall of saidouter wheel and abutting against said casing body, an annular shoulderportion formed in said inner peripheral wall of said outer wheel, anannular thrust plate fixedly disposed in said annular shoulder portionon said outer wheel, and a plurality of thrust bearing rollers disposedbetween said drum member and said thrust plate to transmit the thrustexerted on said drum member to aid casing body through said thrust plateon said annular shoulder portion of said outer wheel.

1. An overrunning clutch comprising an inner wheel having an outerperipheral wall, an outer wheel facing said outer peripheral wall ofsaid inner wheel having an inner peripheral wall, at least threeradially extending projecting portions provided on either one of saidouter peripheral wall of said inner wheel and said inner peripheral wallof said outer wheel at circumferentially equally spaced positions, saidprojecting portions engaging another one of said outer peripheral wallof said inner wheel and said inner peripheral wall of said outer wheel,a plurality of cam surfaces provided on said either one of said outerperipheral wall of said inner wheel and said inner peripheral wall ofsaid outer wheel at circumferentially equally divided positions betweenadjacent said projecting portions, each of said cam surfaces beinginclined at the same angle with respect to the center of saidoverrunning clutch, and a plurality of rollers disposed between said camsurfaces and said another one of said outer peripheral wall of saidinner wheel and said inner peripheral wall of said outer wheel.
 2. Anoverrunning clutch comprising an inner wheel having an outer peripheralwall, an outer wheel having an inner peripheral wall facing said outerperipheral wall of said inner wheel, at least three projection portionsradially inwardly extending from said inner peripheral wall of saidouter wheel at circumferentially equally spaced positions, saidprojecting portions each having a peripheral wall engaging said outerperipheral wall of said inner wheel to prevent eccentricity of saidinner wheel with respect to said outer wheel, a plurality of camsurfaces formed on said inner peripheral wall of said outer wheel atcircumferentially equally divided positions between adjacent saidprojecting portions, each of said cam surfaces being inclined at thesame angle with respect to the center of said overrunning clutch, and aplurality of rollers disposed in between said outer peripheral wall ofsaid inner wheel and said cam surfaces formed on said inner peripheralwall of said outer wheel, said rollers being capable of contacting saidouter peripheral wall of said inner wheel and said cam surfaces on saidouter wheel, whereby said inner wheel is prevented from rotation in onedirection with respect to said outer wheel.
 3. An overrunning clutchcomprising an inner wheel having an outer peripheral wall, an outerwheel having an inner peripheral wall facing said outer peripheral wallof said inner wheel, at least three projecting portions radiallyoutwardly extending from said outer peripheral wall of said inner wheelat circumferentially equally spaced positions, said projecting portionseach having a peripheral wall engaging said inner peripheral wall ofsaid outer wheel to prevent eccentricity of said outer wheel withrespect to said inner wheel, a plurality of cam surfaces formed on saidouter peripheral wall of said inner wheel at circumferentially equallydivided positions between said adjacent projecting portions, each ofsaid cam surfaces being inclined at the same angle with respect to thecenter of said overrunning clutch, and a plurality of rollerS disposedin between said cam surfaces on said inner wheel and said innerperipheral wall of said outer wheel, said rollers being capable ofcontacting said inner peripheral wall of said outer wheel and said camsurfaces on said inner wheel, whereby said outer wheel is prevented fromrotation in one direction with respect to said inner wheel.
 4. Anoverrunning clutch for an automotive automatic power transmission havinga casing body and a drum member, said overrunning clutch comprising aninner wheel connected to said drum member and having an outer peripheralwall, an outer wheel press fitted into a bore of said casing body aflange portion extending radially outwardly from the outer peripheralwall of said outer wheel and abutting against said casing body, anannular shoulder portion formed in said inner peripheral wall of saidouter wheel, an annular thrust plate fixedly disposed in said annularshoulder portion on said outer wheel, and a plurality of thrust bearingrollers disposed between said drum member and said thrust plate totransmit the thrust exerted on said drum member to said casing bodythrough said thrust plate on said annular shoulder portion of said outerwheel.
 5. An overrunning clutch for an automotive automatic powertransmission having a casing body and a drum member, said overrunningclutch comprising an inner wheel connected to said drum member andhaving an outer peripheral wall, an outer wheel press fitted to a boreof said casing body and having an inner peripheral wall, at least threeradially extending projecting portions provided on either one of saidouter peripheral wall of said inner wheel and said inner peripheral wallof said outer wheel at circumferentially equally spaced positions, saidprojecting portions engaging another one of said outer peripheral wallof said inner wheel and said inner peripheral wall of said outer wheel,at least two cam surfaces provided on said either one of said outerperipheral wall of said inner wheel and said inner peripheral wall ofsaid outer wheel at circumferentially equally divided positions betweenadjacent said projecting portions, at least two rollers disposed aboutsaid cam surfaces between said outer peripheral wall of said inner wheeland said inner peripheral wall of said outer wheel, a flange portionextending radially outwardly from the outer peripheral wall of saidouter wheel and abutting against said casing body, an annular shoulderportion formed in said inner peripheral wall of said outer wheel, anannular thrust plate fixedly disposed in said annular shoulder portionon said outer wheel, and a plurality of thrust bearing rollers disposedbetween said drum member and said thrust plate to transmit the thrustexerted on said drum member to aid casing body through said thrust plateon said annular shoulder portion of said outer wheel.